Mooring robot

ABSTRACT

A mooring robot ( 100 ), in a preferred dock-mounted embodiment, includes vacuum cups ( 1, 1 ′) for engagement with the freeboard of a ship. The robot ( 100 ) can position the vacuum cups ( 1, 1 ′) within a three-dimensional operating envelope. A parallel arm linkage having two parallel arms ( 2, 2 ′) pivoted about respective axes which are parallel to the longitudinal axis of the ship are fixed to the dock ( 110 ) for extending and retracting the vacuum cups ( 1, 1 ′) in the transverse direction. The parallel arms ( 2, 2 ′) are fixed to a vertical elongate guide ( 10 ) to which the vacuum cups ( 1, 1 ′) are slidably fixed, the parallel arms ( 2, 2 ′) raising and lowering the vacuum cups ( 1, 1 ′) and maintaining the guide substantially vertical. The vacuum cups ( 1, 1 ′) are mounted for sliding in substantially horizontal track ( 22 ) aligned parallel with the longitudinal axis of the ship for fore and aft movement of the vacuum cups ( 1, 1 ′). Also disclosed is a mooring system comprising a plurality of remotely controlled mooring robots.

TECHNICAL FIELD

[0001] The present invention generally to mooring and more particularly,to robotic mooring devices for mooring large vessels.

BACKGROUND ART

[0002] When mooring a container ship or similar large vessel to a dock,in order to prevent damage to the ship or the dock, it is necessary toprovide a mooring robot that is adequately strong to resist the forcesexerted on it by the action of the wind, waves, passing vessels andtide. The mooring robot must also accommodate relative vertical movementbetween the dock and the ship due to variations in tides anddisplacement. Further, the mooring robot should permit the connectionbetween the ship and the dock to be made or broken quickly withoutdamage to either the dock or the ship. In view of the large size of thevessel typically used, the elements of a mooring robot must bestructurally efficient in order to avoid the necessity of providing alarge and heavy structure to withstand the significant forces which areencountered. It should also desirably have a low energy consumption.

[0003] Another desirable characteristic of a mooring robot, as discussedin WO 0162585, is the ability to absorb loads in the horizontal plane(i.e. external loads applied in the fore and aft direction and/orathwartships) to avoid the effects of impacts which could cause a lossof engagement. The ability to accurately control the position of amoored vessel is also an important requirement.

[0004] A disadvantage of the mooring robot and mooring system describedin WO 0162585, however, is that fore and aft movement and verticalmovement of the vessel relative to the mooring robot are accompanied bya component of movement athwartship, due to the telescoping arm of therobot being pivotably fixed. This feature makes accurately determiningthe position of the attachment elements complicated, and adds to thecomplexity of controlling the mooring robot. Also, since the plane ofthe vacuum cups is not maintained parallel to the surface of the hullwith which it engages, additional wear of the vacuum seals may result asthe cups are often pivoted as they first engage the hull. A furtherdisadvantage of this, and like devices, is that the telescopic booms,being subject to significant bending loads, must be relatively massiveand that, even with the arms retracted, the device requires significantspace at the front mooring face of the dock.

[0005] WO 9114615 describes a mooring device that attempts to overcomesome of the problems associated with the large bending moments exertedby longitudinal movement of the ship, parallel to the face of the dock.One of the solutions proposed is the incorporation of a spherical jointinto a fastening mounted on the ship. Such a design however, requiresthe mooring device to be specially adapted, as well as a large degree ofprecision to align the two mechanical coupling components. Anothersolution is to take the longitudinal loads through stay lines, howeverthe stays obstruct a significant area of the face of the dock.

[0006] All references, including any patents or patent applicationscited in this specification are hereby incorporated by reference. Noadmission is made that any reference constitutes prior art. Thediscussion of the references states what their authors assert, and theapplicants reserve the right to challenge the accuracy and pertinency ofthe cited documents. It will be clearly understood that, although anumber of prior art publications are referred to herein, this referencedoes not constitute an admission that any of these documents form partof the common general knowledge in the art, in New Zealand or in anyother country.

[0007] It is an object of the present invention to address the foregoingproblems or at least to provide the public with a useful choice.

[0008] Further aspects and advantages of the present invention willbecome apparent from the ensuing description which is given by way ofexample only.

DISCLOSURE OF INVENTION

[0009] According to one aspect of the present invention there isprovided a mooring robot for releasably fastening a moored vessel to adock or to a second vessel, the mooring robot including:

[0010] an attractive attachment element releasably engagable with asurface for fastening the moored vessel;

[0011] a substantially vertical elongate guide to which the attachmentelement is slidably fixed, for raising and lowering the attachmentelement;

[0012] a substantially horizontal track to which the attractiveattachment is sidably fixed, the horizontal track being aligned parallelwith a longitudinal axis of the moored vessel for fore and aft movementof the attachment element;

[0013] a parallel arm linkage having two parallel arms each pivotedabout respective axes which are parallel to the longitudinal axis of themoored vessel for extending and retracting the attachment element in atransverse direction, the parallel arms being pivotably fixed to thevertical guide; and

[0014] respective powered actuating means for movement of the attachmentelement in the vertical, longitudinal and transverse directions.

[0015] Preferably the mooring robot is fixed to a mounting framework onthe dock. The parallel arms are connected between the framework and theguide for moving the guide transversely and maintaining the guidevertical during the pivoting movement of the arms. The mooring robotfurther includes a carriage which engages with the vertical guide, andwherein the horizontal track is fixed to the carriage and slidinglyreceives a sub-frame to which the attachment element is fastened.

[0016] Preferably, the attractive element includes vacuum cups, eachhaving circumferential elastomeric seals which define substantiallyplanar face for engagement with a corresponding section of the freeboardof the moored vessel.

[0017] In a preferred embodiment the mooring robot is mounted to a fixedor floating dock. Alternatively, in the case where mooring robot ismounted on the moored vessel, the surface may be, for example, a platefixed to a dock.

[0018] Preferably the actuating means of the parallel arm linkage is alinear actuator which is pivotably connected between the framework andthe vertical guide. Double-acting hydraulic rams may provide theactuating means for both the parallel arm linkage in the transversedirection and the movement of the attachment element relative to thetrack in the longitudinal direction. Preferably an hydraulic accumulatoris connected to both rams for providing a resilient action tending torestore them to a pre-defined operating position.

[0019] Preferably a hydraulic motor driving a loop of chain fixed to thecarriage is employed for raising and lowering the carriage fixed to theguide, but it will be appreciated that other linear actuators may alsobe employed. Means are provided for both fixing the carriage withrespect to the guide and also for allowing it to rise and fallsubstantially freely as required in operation.

[0020] Preferably a spherical joint permits a limited degree of pivotingmovement of the attachment elements relative to the mooring robot.Optionally, a universal joint or a resilient element may be employed forproviding this limited degree of pivoting movement.

[0021] According to another aspect of the present invention there isprovided a mooring system comprising at least one mooring robotsubstantially as described above wherein the operation of each mooringrobot is controlled by a remote controller.

[0022] According to another aspect of the present invention there isprovided a method of operating a mooring system for driving the ship ina longitudinal direction to reposition it along the dock, including thesteps:

[0023] a) providing a mooring system substantially as described above;

[0024] b) determining the desired distance and direction in which theship is to be moved longitudinally;

[0025] c) for each mooring robot in turn, sequentially detaching theattachment element from the hull, moving the attachment element to itsextent of longitudinal travel in a direction opposite to the desireddirection and then reattaching the attachment element;

[0026] d) driving each attachment element in the desired direction; and

[0027] e) repeating step c) and d) until the desired position isreached.

[0028] Preferably, the method includes the further step of sequentiallymoving each attachment element to a neutral position, as hereinbeforedefined.

[0029] This invention provides a mooring robot which is effective inoperational use, and compact making efficient use of the limited spaceavailable at the front mooring face of a dock. The device may beeconomically constructed and has an overall simple but structurallyefficient design that minimizes manufacturing costs and maximizesperformance. It allows for accurate positioning in three dimensions ofthe vacuum cups and maintains the vacuum cups generally parallel to thehull surface throughout its travel.

BRIEF DESCRIPTION OF DRAWINGS

[0030] Further aspects of the present invention will become apparentfrom the following description which is given by way of example only andwith reference to the accompanying drawings in which:

[0031]FIG. 1 is a pictorial view of a preferred embodiment of a mooringrobot of the present invention;

[0032]FIG. 2 is an exploded view of the mooring robot of FIG. 1;

[0033]FIG. 2a shows part of the mooring robot of FIG. 2 from a rotatedviewpoint;

[0034]FIG. 3 is a side elevation of the mooring robot of FIG. 1; and

[0035]FIG. 4 is a plan view illustrating the deployment of mooringrobots of the present invention.

BEST MODES FOR CARRYING OUT THE INVENTION

[0036] Referring to FIG. 1, a preferred embodiment of the mooring robot100 is mounted to a dock 110, fixed adjacent to a front mooring face 112of the dock. The mooring robot 100 includes a pair of vacuum cups 1, 1′which are maintained substantially parallel to the plane of the frontmooring face 112 for engagement with the hull of a vessel (not shown).The mooring robot 100 is capable of positioning the vacuum cups 1, 1′ inthree dimensions, referred to herein as “vertical”, “longitudinal” and“transverse”, wherein “longitudinal” refers to a direction perpendicularto the vertical axis and parallel to the longitudinal axis of the mooredvessel or the front mooring face 112 of the dock.

[0037] The mooring robot 100 is fixed to a framework 113 fastened upon agenerally horizontal surface 11 of the dock. In alternative embodiments(not shown) the mooring robot 100 may be mounted upon a suitablestructure below the surface 111 to maintain the upper surface 11 clearof any obstructions. A parallel arm linkage provides for movement of thevacuum cups 1, 1′ in the transverse direction, and includes parallelupper and lower arms 2, 2′ connected between a pair of columns 114 ofthe framework 113 and a vertical guide 10. A carriage 11 engages withthe vertical guide 10 to provide vertical movement. A sub-frame 12 towhich the vacuum cups 1, 1′ are mounted is slidably engaged with thecarriage 11 for longitudinal movement of the vacuum cups 1, 1′.

[0038] Referring to FIG. 2, each of the arms 2, 2′ is fixed to theframework 113 for pivoting movement about respective longitudinallyextending axes, each arm 2, 2′ being fixed in bearings 3 fastened to thecolumns 114. Likewise, a pivoting connection is provided between thearms 2, 2′ and the guide assembly 10. Power actuation of the transversemovement is provided by a hydraulic ram 4, which is also pivotablyconnected between the framework 113 and the guide assembly 10. It willbe understood that the arms 2, 2′ thus maintain the guide 10 verticalthroughout the transverse movement.

[0039] The guide 10 is an assembly including a pair of parallel elongateguide members 5, 5′ connected by cross members 6, 7 and 8. Fixed to thetop cross member 6 are two hydraulic motors 9, 9′ which are eachconnected to a loop of chain 20 which extends parallel to each of theguide members 5, 5′ and is connected to the carriage 11 for poweractuated raising and lowering thereof.

[0040] The carriage 11 includes vertical channels 21, 21′ for engagementwith the guide members 5, 5′ and a longitudinally extending track 22 inwhich the sub-frame 11 is slidingly received. Longitudinal movement ofthe vacuum cups 1, 1′ is power actuated by hydraulic ram 23 fixed in thetrack 22, the ram 23 being a double-acting type with a continuous pistonrod 24 extending from both ends of the cylinder 23.

[0041] Slidingly received in the track 22, the rectangular sub-frame 11has opposing fixtures 25, 25′ to which opposite ends of the piston rod24 are fixed. In a central part of the sub-frame 12, brackets 26 aresecured for fixing the sub-frame 12 to a mounting beam 27 by means of apin 28 for pivoting about a substantially vertical axis.

[0042] The beam 27 is an intermediate member connecting both the thevacuum cups 1, 1′ to the sub-frame 12 and includes a central aperture 29for receiving the pin 28 and brackets 30, 30′ at opposite ends thereoffor connection to each of the vacuum cups 1, 1′ respectively.

[0043] As illustrated in FIG. 2a, each bracket 30, 30′ has a verticallyextending aperture 31 in which a spherical bearing (not shown) ismounted for engagement a pin 32 to fix the vacuum cups 1, 1′. Thespherical bearing permits a limited degree of angular rotation of thevacuum cups 1, 1′ about two mutually perpendicular axes, and combinedwith pivoting about the axis of the pin 32 provides three degrees offreedom of rotational movement, thus allowing this connection toaccommodate rotations resulting from roll, yaw and pitch of the shipwhen fastened by the mooring robot 100.

[0044] Each mooring robot 100 also includes a hydraulic power pack (notshown) mounted inside the framework 113 and associated controls (notshown). A vacuum pump (not shown) provides means for drawing a vacuum inthe vacuum cups 1, 1′. Vacuum and hydraulic connections are by means offlexible hoses (not shown). For control of the robot, movement of thevacuum cups 1, 1′ in each of the dimensions is measured by respectivelinear position sensors (not shown). This position information togetherwith hydraulic pressures in the rams 4 and 23 and vacuum measured ineach vacuum cup 1, 1′ is monitored by a robot control computer (notshown) and transmitted as required to a remote controller (not shown)which, in the preferred embodiment controls a mooring system comprisingat least two pairs of mooring robots 100.

[0045] Referring to FIG. 3, to make fast a ship, the vacuum cups 1, 1′are extended from the front mooring face 112 when a ship 200 approaches.The arms 2, 2′ rotate between a retracted position (not shown) to thepartially extended position (as shown in FIG. 3) through an angle A. Theangle A being approximately 90 degrees at maximum horizontal travel. Themooring robot 100 extends the vacuum cups 1, 1′ out to engage a planarsection of the hull. Each vacuum cup, 1, 1′ has a peripheral seal 40 anda plurality of abutments 41 (see FIG. 1) which prevent which preventover deformation of the seal 40. The vacuum cups 1, 1′ are able torotate to conform to any curve of the hull. Most bulk, passenger andcontainer ships in particular have sides that are substantially planarand parallel to the front face of the dock 112, except possibly near thebow and stern of the ship which are not used for mooring using themooring robot 100. Sensors (not shown) indicate engagement with thehull. The vacuum cups 1, 1′ are then evacuated to fasten to the ship inthe known manner, before actuating the mooring robot 100 to move theship to the desired moored position. When the desired moored position isreached the vacuum pump may be stopped, with a vacuum accumulator (notshown) in the line to the vacuum cups 1, 1′ maintaining the vacuum.

[0046] Optionally, the method of mooring the ship includes a first stepof initially selecting the height of the vacuum cups 1, 1′ depending onthe state of the tide and state of loading of the ship. In this way thevertical travel required to be accommodated may be reduced. In themoored position, each mooring robot 100 is in a ‘neutral’ position, anintermediate position near the centre of its longitudinal and transversetravel. Preferably, in the neutral position the robots are at varyingheights, such that they do not all simultaneously reach the limits oftheir vertical travel.

[0047] Each mooring robot 100 maintains the ship, within certain limits,in the moored position in response to changing conditions of wind, tide,swell and displacement. On attaining the desired moored position thehydraulic pump (not shown) is stopped and an accumulator (not shown) iscut into the lines to the rams 4 and 24, thus providing a resilientaction. When displaced from the predefined moored positionlongitudinally or transversely by external forces the accumulator ispressurised and provides hydraulic pressure to the rams 4, 23 tending torestore the ship to the moored position The hydraulic motors 9, 9′ (orlinear actuators, if used) for raising and lowering the vacuum cups 1,1′ are switched into a free-floating mode allowing the carriage 11 (andthus the ship 200) to rise and fall with the tide, state of loading,etc.

[0048] As shown in FIG. 5, a mooring system in the illustratedembodiment includes two pairs of mooring robots 100, which are installedbetween energy-absorbing fenders placed at intervals along the frontface of the dock 12. Providing the mooring robots 100 in pairs, eachhaving an independent hydraulic and vacuum supply provides a level ofredundancy for safety. Each of the mooring robots 100 is connected by awireless link to a remote control unit mounted aboard the ship 200. Theremote control transmits a signal to each mooring robot 100 to controlits position and operation, and receives feedback of actual position andoperating conditions. Positional feedback indications from each mooringrobot 100 can be provided to other systems, for example, automaticloading systems which require information on the position of the ship.

[0049] Under most conditions the operation of the mooring robots 100 iscoordinated, for example, when mooring and unmooring the ship, or whenperforming vertical or horizontal stepping movements, as described in WO0162584. In severe conditions, monitoring of hydraulic pressures andvacuum in the vacuum cups 1, 1′ allows the performance of the system toadjusted accordingly, for example, by running the vacuum pumpcontinuously to maintain a higher vacuum when required.

[0050] Under normal conditions when the mooring robot 100 approaches theextent of its vertical travel the system initiates a stepping sequencemoving each mooring robot 100 alternately in a stepwise manner, howeverin a highly loaded state, stepping may be prevented to ensure securityof the vessel, with the system indicating an alarm condition. A warningis also indicated when the system is approaching its holding capacity,allowing the ship's captain to take emergency action.

[0051] Movement of the mooring robots 100 may also be coordinated fordriving the ship fore and aft to reposition it along the dock, asrequired. For example, to drive the ship forward, the vacuum cups 1, 1′of each mooring robot 100 are sequentially detached from the hull, movedto their extent of aft travel and then reattached. With all the vacuumcups 1, 1′ at their aft extent, they are all driven together to theirforward extent. To move the ship further than the limit of horizontaltravel, this process may be repeated in a stepwise manner. Once thislongitudinal movement is completed, each mooring robot 100 is returnedto a neutral position.

[0052] Aspects of the present invention have been described by way ofexample only and it should be appreciated that modifications andadditions may be made thereto without departing from the scope thereof.

1. A mooring robot for releasably fastening a moored vessel to a dock orto a second vessel, the mooring robot including: an attractiveattachment element releasably engagable with a surface for fastening themoored vessel; a substantially vertical elongate guide to which theattachment element is slidably fixed, for raising and lowering theattachment element; a substantially horizontal track to which theattractive attachment is slidably fixed, the horizontal track beingaligned parallel with a longitudinal axis of the moored vessel for foreand aft movement of the attachment element; a parallel arm linkagehaving two parallel arms each pivoted about respective axes which areparallel to the longitudinal axis of the moored vessel for extending andretracting the attachment element in a transverse direction, theparallel arms being pivotably fixed to the vertical guide; andrespective powered actuating means for movement of the attachmentelement in the vertical, longitudinal and transverse directions.
 2. Themooring robot of claim 1 fixed to a mounting framework on the dock,wherein the parallel arms are connected between the framework and theguide for moving the guide transversely and maintaining the guidevertical during the pivoting movement of the arms; the mooring robotfurther including a carriage which engages with the vertical guide, andthe horizontal track is fixed to the carriage and slidingly receives asub-frame to which the attachment element is fastened.
 3. The mooringrobot of claim 1 or claim 2 said surface is substantially planar and atleast part of the attachment element defines a correspondingsubstantially planar face, the parallel arm linkage maintaining theplanar face substantially parallel with surface throughout thetransverse movement of the attachment element.
 4. The mooring robot ofany one of claims 1 to 3 wherein the mooring robot is mounted to a fixedor floating dock.
 5. The mooring robot of any one of claims 1 to 4wherein the attractive element comprises one or more vacuum cups, andsaid surface is a section of the freeboard of the moored vessel.
 6. Themooring robot of any one of claims 2 to 5 wherein the actuating means ofthe parallel arm linkage is a linear actuator pivotably connectedbetween the framework and the vertical guide.
 7. The mooring robot ofany one of claims 1 to 6 wherein double-acting hydraulic rams providethe actuating means for both the parallel arm linkage in the transversedirection and the movement of the attachment element relative to thetrack in the longitudinal direction.
 8. The mooring robot of claim 7wherein a hydraulic accumulator is connected to both rams for providinga resilient action tending to restore them to a pre-defined operatingposition.
 9. The mooring robot of any one of claims 1 to 8 furtherincluding means for both fixing the carriage with respect to the guideand also for allowing it to rise and fall substantially freely asrequired in operation.
 10. A mooring system comprising one or moremooring robots as claimed in any one of claims 1 to 9 wherein theoperation of each mooring robot is controlled by a remote controller.11. The mooring system as claimed in claim 10 wherein four mooringrobots are mounted to a dock in two pairs.
 12. A method of operating amooring system for driving the ship in a longitudinal direction toreposition it along the dock, including the steps: a) providing amooring system as claimed in claim 11; b) determining the desireddistance and direction in which the ship is to be moved longitudinally;c) for each mooring robot in turn, sequentially detaching the attachmentelement from the hull, moving the attachment element to its extent oflongitudinal travel in a direction opposite to the desired direction andthen reattaching the attachment element; d) driving each attachmentelement in the desired direction; and e) repeating step c) and d) untilthe desired position is reached.
 13. The method of operating a mooringsystem as claimed in claim 12 further including the step: f)sequentially moving each attachment element to a neutral position, ashereinbefore defined.
 14. A mooring robot substantially as hereinbeforedescribed with reference to the accompanying drawings.
 15. A mooringsystem substantially as hereinbefore described with reference to theaccompanying drawings.